There is some RNG seeding that seems to take place at the opening splash screen (when the music starts). It determines who the CPU will select as your opponents.

If you mash start when the game boots up (presumably skipping the first screen on the first frame), you'll get Stonewall/Newts, which is (IMO) a sub-optimal matchup. Maybe even the worst matchup. These guys will body you and steal the ball constantly.

If you wait all the way through the opening screen without hitting any buttons, you'll get Xaos and T-Bone. This is probably not the ideal matchup, but it's much better than Stonewall/Newts.

Other RNG seeds can be accessed by skipping the opening screen at specific points. It helps to time it with the music if you're going for a particular combo.